Invention relates to the field of microscopy and more specifically to microcompressors which serve to restrict the motion of living, microscopic organisms under observation as viewed with the aid of a microscope.
Known art includes, in its simplest form, an apparatus similar to a pill box and having glass elements, as its top and bottom that are mounted in metal frames provided with mating threads. An organism to be observed was placed in a drop of liquid on the lower glass element, the top half metal frame was than threaded onto the lower half until the liquid was in contact with both glass elements and, by continuing to turn the top half frame with respect to the bottom half frame, the opposing inner glass surfaces were brought together so as to lightly restrain the living organism. The disadvantage of this apparatus lay in the difficulty of adjustment and the tendency for unwanted lateral displacement of the organism.
Another example of prior art is in apparatus which comprises a metal base, a glass element mounted in said base, a second metal element hinged at one end of the base and extending over the length of the base, a second glass element mounted in the hinged, second metal element over the glass element mounted in the base, and an adjusting screw whereby the distance between the opposing inner glass surfaces can be varied. An organism to be observed is placed in a drop of liquid on the lower glass element, the hinged metal element is lowered into position and the adjusting screw is turned until the liquid is in contact with both glass elements, and, by continuing to turn the adjusting screw, the opposing glass surfaces are brought together so as to lightly restrain the living organism. The disadvantage of this apparatus lies in the fact that the inner, opposing surfaces of the glass elements can be made parallel in only one setting of the adjustment, while the size of organisms to be observed varies considerably. As a result of this, the apparatus is characterized by unwanted lateral displacement.
Another example of prior art is an apparatus which comprises a metal base, a glass element mounted in said base, a second glass element over the first element mounted in a metal arm extending from a hub on a fixed column located near one end of the metal base. The hub is movable on said fixed column so as to permit rotation of the hub whereby the second glass element can be displaced laterally with reference to the first and displaced perpendicularly whereby the separation between the opposing, inner glass surfaces can be varied. The hub is supported by a helical compression spring and adjustment effected by means of an adjusting screw which bears against the hub. The disadvantage of this apparatus lies in the fact that there is no isolation between the rotary motions of the adjusting screw and the hub. Hence rotation of the adjusting screw imparts rotation to the hub and causes unwanted lateral displacement of the organism for all except one position in which such movement is prevent by a hub-mounted detent which seats in a vertical groove in the column.
Although unwanted displacement is highly objectionable, it is very useful, during observation of an organism, to be able to induce controlled displacement whereby the microscopic object being observed can be rolled over for the purpose of obtaining a view from a different aspect. The disadvantage of this apparatus lies in the fact that the detent is usually out of its related groove and adjustment usually is accompanied by unwanted displacement.
A further disadvantage with this apparatus lies in the fact that the area of the glass element mounted in the adjustable arm is so small, and the location of the adjusting mechanism is so near to it that it is impossible to change from one microscope objective to another without interfering with the adjustable arm or the adjusting mechanism of microscopes equipped with revolving objective changers. A further disadvantage with this apparatus lies in the fact that the dimension from the bottom of the metal, base plate to the upper surface of the glass element, mounted in it, exceeds the focal length of many modern substage condensers. This condition results in degradation of the image.